Masters of the V-12
They're like highly specialized surgeons: there are few of them and they're in great demand.
- By Stephan Wilkinson
- Air & Space magazine, March 2002
(Page 6 of 7)
“See that semi out there?” Moja asks, pointing to a battered white trailer outside the shop. “It’s filled with cylinder heads that prove you can overboost an Allison.” Sandberg began his short air-racing career with an Allison-powered Bell P-63 Kingcobra. An inveterate tinkerer, he continually had its engine modified in a variety of ways, never leaving well enough alone. “We modified and modified that engine and kept blowing it up,” Moja says. “Then we finally took it back to stock and it ran better than ever.”
“There are no tricks to building a good engine,” Sam Torvik says. “Everybody thinks there’s magic involved, but there isn’t. You just have to build it right and use the best parts. It’s becoming harder and harder to find them, though. When you keep blowing these things up racing them, where are you going to get parts for your regular customers?”
Some of the simplest yet most difficult-to-find parts—new crank and rod bearings, for example—would be easy for a competent fabricator to manufacture, “but the people who could do it don’t want the liability,” Torvik points out. Torvik and Moja blame “the boat people” for the dearth of parts. “When the hydroplane guys found out they could use Merlins and Allisons [for Gold Cup racing], it drove the value of a core from $250 to $25,000,” Moja says. “And then the tractor-pullers came along. Then when they screwed up all the engines they could find, they went to turbines. If I get a call from a tractor-puller looking for parts, I won’t even talk to him.”
The heart of a Merlin or Allison engine—“the core”—never wears out, unless the ravages of time simply corrode it beyond redemption or racing use overstresses it. The crankcase and crankshaft, cylinder banks, accessory-case and valve covers, heads and cams, supercharger, propeller reduction gears, and various pumps and fittings are usually salvageable. During a serious rebuild, new pistons, rings, bearings, valves, springs, camshafts and followers go into the core, and the cylinder liners are bored slightly oversize. Sometimes, all that’s needed are new seals, gaskets, and O-rings.
But that won’t be enough to help a buyer who has fallen for the bargain price of a former hydroplane engine. The main clue that the engine’s been on the water is nonstandard fittings for oil-scavenge pumps at the aft end of each head, which are necessary because the engines sit at an angle in boat-racing. They live a short life turning at very high revs, with the prop jumping in and out of the water, and their cores are useless for anything but…well, boat anchors.
Of course the air racers destroy engines too. “Yeah, but they only do it once a year,” Torvik says.
For all these men, building V-12s is not so much a profession as a calling. And the nature of the priesthood is unlikely to draw young airframe-and-powerplant graduates who have airline companies beating down their doors. If the V-12 business weren’t turning at least a modest profit, none of these shops could afford to pay the light bill. But you get the feeling it’s not about the money.